KR101179334B1 - Manufacturing method of organic electrode for transparent electrode - Google Patents

Abstract

The present invention comprises the steps of preparing an organic conductive composition comprising a conductive material, a binder and a solvent; Providing a substrate on which a cutting line divided into cells is formed; Printing a conductive pattern using the organic conductive composition in each cell partitioned by a cutting line to form a conductive layer; And dicing along a cutting line to separate the cells into cells in which the conductive layers are formed, respectively.
According to an embodiment of the present invention, it is possible to provide a method of forming a transparent organic electrode having a low defect rate and low consumption of raw materials and having excellent transparency.

Description

Manufacturing method of organic electrode for transparent electrode

The present invention relates to a method for forming a transparent organic electrode, and more particularly, to a method for forming a transparent organic electrode having a low defect rate and low raw material consumption and excellent transparency.

As computers, various home appliances, and communication devices are digitized and rapidly improved in performance, there is an urgent need for the implementation of large screens and portable displays. In order to realize a large, portable display that is portable, a display material made of a material that can be folded or rolled like a newspaper is required.

To this end, the display electrode material should not only exhibit transparent and low resistance values, but also have high strength to be mechanically stable even when the device is bent or folded, and has a coefficient of thermal expansion similar to that of plastic substrates. Even if overheated or hot, there should be no short-circuit or change in surface resistance.

Flexible displays allow the manufacture of displays of any shape, so they can be used not only for portable display devices, but also for apparel or clothing labels, billboards, price signs on product shelves, large-scale electric lighting devices, etc. that can change colors or patterns. Its utilization is high.

At present, a method for manufacturing a transparent conductive material at home and abroad is applied to form a conductive layer by applying various metal oxides such as indium, tin, zinc, titanium, cesium, etc. using chemical vapor deposition, magnetron sputtering and reactive evaporation deposition on a substrate. Is actively underway. However, in order to coat the metal oxide on the substrate as described above, vacuum conditions are required, resulting in an expensive process cost.

Here, the transparent conductive material formed by coating the metal oxide on the large area substrate is cut into cells of a unit required by the user and provided to the user. However, the rate of cracking at the cutting surface of the transparent electrode, that is, at the edge of the unit cell due to the mechanical stress in the cutting process is very high, the production yield of the transparent electrode is very low.

In addition, as the process of removing the conductive layer at the site where the electrode is to be attached is attached to attach the electrode to the transparent conductive material on which the metal oxide conductive layer is formed, an increase in manufacturing price is caused.

The present invention is to solve the above problems, an object of the present invention is to provide a transparent organic electrode forming method having a low defect rate and low consumption of raw materials and excellent transparency.

In order to solve the above problems, a method of forming a transparent organic electrode according to an embodiment of the present invention comprises the steps of preparing an organic conductive composition comprising a conductive material, a binder and a solvent; Providing a substrate on which a cutting line divided into cells is formed; Printing a conductive pattern using the organic conductive composition in each cell partitioned by a cutting line to form a conductive layer; And dicing along the cutting line to separate the cells into the conductive layers.

In the forming of the conductive layer, one conductive pattern may be printed in each cell.

In the forming of the conductive layer, two or more conductive patterns may be printed in each cell.

The conductive pattern may be printed in a circular or polygonal pattern.

The organic conductive composition may further include a viscosity modifier.

The conductive material may be made of at least one material of a conductive polymer, a metal nanomaterial, a carbon nanotube, and a conductive ink.

The conductive polymer may be poly-3, 4-ethylenedioxythiophene / polystyrenesulfonate (PEDOT / PSS) or polyaniline.

The conductive material is preferably 3 to 50 parts by weight based on 100 parts by weight of the total composition, and the binder is preferably 1 to 40 parts by weight based on 100 parts by weight of the total composition.

After the forming of the conductive layer, the method may further include heat treating the conductive layer.

The heat treatment of the conductive layer is preferably performed at room temperature to 400 ° C, more preferably may be heat treatment at 25 to 150 ° C.

The conductive pattern may be formed by inkjet printing, screen printing, gravure printing, or offset printing.

According to the present invention, it is possible to provide a method for forming a transparent organic electrode having a low defect rate and low consumption of raw materials and having excellent transparency.

In addition, as the heat treatment and dicing of the organic conductive composition printed on the substrate eliminates the need for transparent separate electrode formation, the manufacturing process of the organic electrode is simplified.

1A to 1C are flowcharts illustrating a process of forming a transparent organic electrode according to an embodiment of the present invention.
2A and 2B are perspective views illustrating a cell according to another embodiment of the present invention.
3 is a graph showing the change rate and crack generation rate of the cell resistance according to the heat treatment temperature.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. In addition, the embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art. Accordingly, the shape and size of elements in the drawings may be exaggerated for clarity, and the elements denoted by the same reference numerals in the drawings are the same elements.

Hereinafter, a transparent organic electrode forming process according to an embodiment of the present invention will be described with reference to FIGS. 1A to 1C.

1A is a perspective view schematically illustrating a process of forming conductive patterns spaced at predetermined intervals using an organic conductive composition on a substrate according to an embodiment of the present invention, and FIG. 1B is a perspective view of the substrate on the substrate according to an embodiment of the present invention. 1C is a perspective view schematically illustrating a process of cutting, on a cell-by-cell basis, a substrate on which a conductive pattern heat-treated according to an embodiment of the present invention is formed.

According to an embodiment of the present invention, the conductive pattern is printed in the form of a pattern, thereby manufacturing a cell in which the conductive layer is formed. The cell refers to the smallest unit of electrical device capable of performing an electrical function.

According to an embodiment of the present invention, a plurality of cells may be manufactured by cutting the substrate in cell units. A plurality of cells may be manufactured by forming a cutting line divided into cells on the substrate and cutting the cells along the cutting lines by a cell unit.

Each cell divided by a cutting line on the substrate may be printed with one conductive pattern to form a conductive layer, or two or more conductive patterns may be printed to form a conductive layer. In addition, the conductive pattern may be printed in a single pattern used in a resistive method in a touch screen, and may be printed in a circular or polygonal pattern such as a bar, triangle, and diamond used in the capacitive method.

In addition, a conductive electrode electrically connected to the conductive pattern (hereinafter, referred to as a conductive pattern and connected to an FPC) may be printed on each cell before the cutting process of cutting in cell units, and after printing, the conductive pattern may be formed. The substrate may be cut cell by cell along the cutting line.

As the material constituting the conductive pattern, a material such as silver paste having excellent conductivity may be used.

First, the substrate 10 is partitioned through the cutting lines CL in units of cells. The cutting line CL may be displayed on a substrate and may be imaged through an image processing process of the substrate 10. After forming the conductive layer, the cutting line CL may be diced to form a plurality of cells.

One or more conductive patterns 33 spaced at predetermined intervals are formed using the organic conductive composition 30 inside each cell partitioned by the cutting lines CL on the substrate 10. The organic conductive composition 30 is printed on the substrate 10 in a pattern form to form a conductive pattern 33. The conductive pattern 33 is printed spaced apart at predetermined intervals.

When the substrate is cut in cell units along the cutting line CL so that one or more conductive patterns 33 are included in one cell, the conductive layer constituting each of the cells is formed by one or more conductive patterns 33. Is done.

Preferably, one conductive pattern 33c may be formed in one cell (see FIG. 1C), or two or more conductive patterns 33d and 33e may be formed in one cell (see FIG. 2). .

In this manner, a cell having the conductive pattern 33 is formed, and thus, a conductive layer in which the organic conductive composition is printed in a pattern form is formed in each of the plurality of cells.

The substrate 10 is not particularly limited as long as it is a material that is easy to form the conductive pattern 33 on one surface, and resin, glass, or the like may be used.

The substrate 10 may be a colored or colorless material depending on the use, and preferably, when the substrate 10 is provided as a display surface of the display device, a transparent material may be used. For example, polyethylene terephthalate (PET), polycarbonate (PC), or polymethyl methacrylate (PMMA), polyethylene naphthalate (PEN), polyethersulfone (PES), cyclic olefin polymer (COC), etc. Resin, glass, tempered glass, or the like can be used as the material of the substrate 10.

In the present specification, transparent includes colorless transparent, colored transparent, translucent, colored translucent, and the like.

Here, the organic conductive composition 30 may include a conductive material, a binder, a solvent, and the like.

Here, the conductive material may be made of at least one material of a conductive polymer, a metal nanomaterial, a carbon nanotube (or carbon black), and a conductive ink.

In particular, the conductive polymer is not particularly limited, and for example, poly-3,4-ethylenedioxythiophene / polystyrenesulfonate (poly-3,4-ethylenedioxythiophene / polystyrenesulfonate, PEDOT / PSS) or polyaniline alone or the like It can be mixed and used.

The content of the conductive polymer may be 3 to 50 parts by weight based on 100 parts by weight of the total composition. If the content is less than 3 parts by weight, the electrical conductivity may be lowered. If the content is more than 50 parts by weight, the solubility may be lowered or the transparency may be lowered.

The binder included in the organic conductive composition 30 of the present invention serves to improve the adhesive force of the organic conductive composition. The binder may comprise a water soluble low molecular weight binder or a water soluble high molecular weight binder, or both. Examples of the binder include alkyl glycidyl ether (meth) acrylates having 2 to 8 carbon atoms, phenylglycidyl ether (meth) acrylates, (meth) acrylates, and polyfunctional (meth) acrylates. It can be used alone or in combination.

The content of the binder may be 1 to 40 parts by weight based on 100 parts by weight of the total composition. If the content is less than 1 part by weight, the adhesion to the substrate may be lowered. If the content is more than 40 parts by weight, the electrical conductivity may be lowered.

The solvent included in the organic conductive composition of the present invention is not particularly limited, but polyalcohol, dimethyl sulfoxide (DMSO), N, N-dimethylformamide (N, N-diemthylformamide), ethylene Glycol (ethylene glycoll; EG), meso-erythritol, water and the like can be used.

The content of the solvent may be 2 to 40 parts by weight based on 100 parts by weight of the total composition. If the content is less than 2 parts by weight it may be difficult to uniformly mix between compositions, if the content exceeds 40 parts by weight there is a fear that the electrical conductivity is lowered.

In the present invention, the organic conductive composition 30 may include a viscosity modifier to adjust the viscosity of the organic conductive composition according to a printing method applied to the formation of the conductive pattern 33. Although not limited thereto, the viscosity of the organic conductive composition 30 may be adjusted to preferably 400 mPas or less, more preferably 60 to 200 mPas.

The viscosity modifier included in the organic conductive composition 30 of the present invention is not particularly limited, and a viscosity modifier of an organic component may be used.

The viscosity of the organic conductive composition 30 is preferably adjusted according to the printing method. If the viscosity is too strong or too weak, it cannot be applied to printing and it becomes difficult to form a conductive pattern on the substrate, so it is necessary to adjust the viscosity modifier to have an appropriate viscosity.

In order to prepare an organic conductive composition having an appropriate viscosity, the content of the viscosity modifier may be 0 to 40 parts by weight based on 100 parts by weight of the total composition.

If the content of the viscosity modifier is less than 0 parts by weight, it may be difficult to adjust to the desired viscosity, if the content exceeds 40 parts by weight there is a fear that the electrical conductivity is lowered.

The formation method of the conductive pattern 33 using the organic conductive composition 30 is not particularly limited, and for example, inkjet printing, screen printing, gravure printing, or offset printing may be used. More specifically, the organic conductive composition 30 may be appropriately adjusted in viscosity according to the printing method applied.

When heat-treating the organic conductive composition 30, but not limited thereto, it is preferable to heat-treat at room temperature to 400 ° C, or more preferably at 25 ° C to 150 ° C. If the heat treatment temperature of the organic conductive composition 30 is low, the viscosity of the composition may be lowered, and if the heat treatment temperature is high, the organic conductive composition 30 may be deformed.

As described above, as the viscosity is adjusted, the organic conductive composition 30 provided in the nozzle 20 is dropped by using a printing method to form a plurality of conductive patterns 33 spaced at predetermined intervals on the substrate 10. Can be.

The substrate 10 is cut in cell units along the cutting line CL. One cell is cut to include one or more conductive patterns 33.

The cutting line CL is formed according to the size and shape of the desired cell, and the cutting line CL is then cut to form an edge of the cell.

According to one embodiment of the present invention is cut to form a single pattern of conductive pattern 33c in one cell (FIG. 1C), and according to another embodiment of the present invention four circular conductive patterns in one cell 33d is cut, and according to another embodiment of the present invention, four square conductive patterns 33e are formed in one cell.

Subsequently, the conductive pattern 33 formed on the substrate 10 may be heat-treated according to an exemplary embodiment of the present invention to improve adhesion between the heat-treated conductive pattern 33 ′ and the substrate 10.

In addition, in order to improve the adhesion of the conductive pattern, the substrate 10 may be improved by UV (ultraviolet) irradiation, corona treatment, or primer treatment.

Next, the conductive pattern 33 ′ formed on the large-area substrate 10 and heat-treated is diced in units of cells C along the cutting lines CL formed on the substrate using the blade 40 or the like, and then united. The transparent organic electrode which is the cell C in which the conductive pattern 33C was formed on 10C is manufactured.

In the case of a conventional conductive pattern using ITO, a pattern is formed by depositing, exposing, and developing the entire substrate, and then cutting the unit cell into a unit cell, which consumes a lot of raw materials and has a complicated process.

In addition, in the case of the conductive pattern using ITO or the like, there is a high possibility of cracking during the dicing process due to the material properties of the inorganic material.

According to the present embodiment, the organic conductive composition 30 is printed on the substrate 10 in the form of a conductive pattern constituting the unit cell, thereby providing only the organic conductive composition 30 in an amount necessary to form the unit cell. Can be used to reduce the consumption of raw materials.

In addition, in the conventional dicing process, since the conductive pattern is cut directly, a lot of cracks are generated at the edge of the conductive pattern. The pattern is printed so that at least two conductive patterns are formed, and the conductive patterns are not cut directly by cutting along the cutting lines CL in units of cells.

That is, since the cutting line CL formed on the substrate 10 is cut, it is possible to prevent the generation of cracks generated by cutting the pattern.

Therefore, since the organic conductive composition 30 is not printed on the entire substrate 10, raw material consumption is reduced, and since the conductive pattern is not directly cut, the crack incidence rate may be reduced to improve the transparent electrode manufacturing yield.

In addition, since the heat-treated conductive pattern 33 ′ itself may serve as an electrode, a process of removing the conductive layer at an electrode attachment site is unnecessary in order to attach the electrode to an existing transparent conductive material. This simplifies and reduces the manufacturing cost.

Example 1

In order to investigate the rate of change of the resistance according to the heat treatment temperature of the organic conductive composition, after the printing using inkjet printing, screen printing, gravure printing or offset printing method was heat treated for 30 minutes to compare the resistance of the cell by the heat treatment temperature.

3A is a graph illustrating a change rate of resistance according to a heat treatment temperature in various printing methods.

When the organic conductive composition was printed by various printing methods and then heat treated between 25 ° C. and 150 ° C., the resistance of the unit cell containing the organic conductive composition did not increase significantly, but the resistance rapidly increased with increasing 150 ° C. It can be seen that increased.

That is, according to an embodiment of the present invention, when the heat treatment at a temperature of 25 ° C to 150 ° C can be produced unit cell having a constant resistance, while the heat treatment temperature exceeds 150 ° C As a result, the properties of the organic conductive composition were changed, and it was found that the resistance increased rapidly.

[Example 2]

In various printing methods, in order to investigate the crack generation rate according to the heat treatment temperature of the organic conductive composition after printing, using the inkjet printing, screen printing, gravure printing and offset printing method and then heat-treated for 30 minutes, the crack generation rate for each temperature I saw a comparison.

The crack generation rate (A) is based on the ratio of the length of cracks per unit length when cracks are generated in a unit area, so that the more cracks, the larger the crack generation rate value.

Crack Generation Rate = Crack Length / Unit Length

Referring to Figure 3b, according to an embodiment of the present invention to form a cutting line for partitioning each cell, the printing of the conductive pattern in each cell partitioned by the cutting line when the heat treatment at 100 ° C or less Even if the method was applied, the crack generation rate did not exceed 0.5, and especially when heat-treated at 50 ° C or below, the crack generation rate did not exceed 0.3 regardless of the printing method.

In addition, the crack generation rate did not exceed 0.2 when the organic conductive composition was heat treated at 50 ° C. or lower after printing by the gravure printing method and the inkjet printing method.

In other words, no matter what printing method is applied, in the range of 25 ° C. to 150 ° C., when the heat treatment is performed, the crack generation rate (A) has a value of less than 1. However, if the heat treatment temperature exceeds 150 ° C crack generation rate (A) exceeds 1, the failure rate of the unit cell increased.

According to an embodiment of the present invention, because the organic conductive composition is used, the organic compound is deformed at a high temperature, so the crack generation rate of the electrode is increased, but the unit cell is heat-treated in the temperature range where the thermal deformation of the organic material does not occur. In the case of manufacturing the crack generation rate does not exceed 1, in particular when the heat treatment at a temperature of less than 100 ° C no matter what printing method has a crack generation rate of less than 0.5 was found that the electrode failure rate is significantly lowered.

Claims (13)

Preparing an organic conductive composition comprising a conductive material, a binder, a solvent and a viscosity modifier;
Providing a substrate on which a cutting line divided into cells is formed;
Forming a conductive layer by printing a conductive pattern using the organic conductive composition in each cell partitioned by the cutting lines; And
Dicing along the cutting line to separate into cells each having a conductive layer formed thereon;
Transparent organic electrode forming method comprising a.
The method of claim 1,
In the step of forming the conductive layer,
A method of forming a transparent organic electrode for printing one conductive pattern inside each cell.
The method of claim 1,
In the step of forming the conductive layer,
A method of forming a transparent organic electrode for printing a plurality of conductive patterns inside each cell.
The method according to claim 2 or 3,
The conductive pattern is a transparent organic electrode forming method of a circular or polygonal pattern.
delete The method of claim 1,
The conductive material is a transparent organic electrode forming method consisting of at least one of a conductive polymer, a metal nanomaterial, a carbon nanotube and a conductive ink.
The method of claim 6,
Wherein the conductive polymer is poly-3, 4-ethylenedioxythiophene / polystyrenesulfonate (PEDOT / PSS) or polyaniline.
The method of claim 1,
The conductive material is a transparent organic electrode forming method, characterized in that 3 to 50 parts by weight based on 100 parts by weight of the total composition.
The method of claim 1,
The binder is a transparent organic electrode forming method, characterized in that 1 to 40 parts by weight based on 100 parts by weight of the total composition.
The method of claim 1,
After forming the conductive layer,
The method of forming a transparent organic electrode further comprising the step of heat-treating the conductive layer.
The method of claim 10,
Heat-treating the conductive layer is a transparent organic electrode forming method, characterized in that performed at room temperature to 400 ° C.
The method of claim 10,
Heat-treating the conductive layer is a transparent organic electrode forming method, characterized in that performed at 25 to 150 ° C.
The method of claim 1,
And the conductive pattern is formed by inkjet printing, screen printing, gravure printing, or offset printing.

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